Using large-capacity battery systems has increasingly become an essential element in some technical fields. For instance, the automobile industry is experiencing a dramatic shift from the age of hybrid automobiles to the age of electric automobiles. Implementing such a large-capacity battery systems is the key element for bringing about a new age in automobiles. In such a large-capacity battery systems, a large number of battery cells are connected to one another to provide the desired amount of voltage and current.
As such battery systems combining a large number of battery cells come into widespread use, the lives of the battery cells will expire after some years and the battery systems will need to be disposed of or recycled.
When disassembling the battery systems, one or more of such battery cells have a non-negligible level of charge remaining. In the battery systems combining a large number of the battery cells, there may be cases where a considerable amount of energy remains. When an attempt is made to disassemble the coupled battery cells into single cells, if the cells have a certain amount of charge remaining, the balance of the entire battery system will be lost. This results in a phenomenon that a reverse current flows from some cells to cells that have become relatively weaker and have a relatively lower voltage than the other cells. This phenomenon may cause an undesirable consequence. No method of safely disassembling a battery system has been provided so far.
In view of these issues, there is a demand for a configuration and method of safely and readily electrically separating a battery assembly composed of used unit cells into single unit cells at the time of disassembly.